The field of the present invention generally relates to data reading apparatus. More particularly, the field of the present invention relates to a method and apparatus for scanning items such as those bearing a bar code symbol.
Bar code scanners are well known for scanning the universal product code ("UPC") and other types of bar codes on packages or containers, particularly in retail stores. Generally, in retail stores, bar code scanners are set up at check-out stands or are built into a horizontal check-out counter so that a laser beam is scanned up through a transparent window, defining a number of different scan lines. Normally, packages are placed by the customer on a counter, deck or conveyor. A check-out person then takes each package, visually locates the UPC or other bar code label on a surface of the package and moves the package through the laser's scanning area.
Handheld devices have also been employed to read bar codes. One such handheld device is the wand. The wand has a detector positioned in its tip which is manually drawn across the bar code. In such a device, the wand must be oriented in the proper fashion and drawn across the bar code at the correct speed and preferably in the proper direction. For each complete pass across the bar code, the wand has one opportunity (i.e., one scan) to make a read. Wands frequently require repeated passes across the bar code to achieve a successful read.
Another device is the bar code scanner such as shown in U.S. Pat. No. 5,146,463, to Joseph Rando, which is a handheld scanning device. The scanner body is generally in the shape of a gun which may be pointed or aimed at the bar code. The user activates the scanning beam by actuating a trigger switch, turning on the laser light source which generates a laser beam. The laser beam is reflected off a rotating polygon mirror to produce a multitude of scanning sweeps across the bar code. The scanner may also generate an aiming beam to aid aiming of the scanned beam.
In some applications, it is desirable for the operator to have a data terminal associated with the reader apparatus. A data terminal typically comprises a key pad to permit manual data entry. There have been attempts to integrate a reading device, such as a handheld scanner, with a data terminal. One such device is the Symbol Technologies LRT3800 scanner/portable data terminal system in which a portable data terminal is mounted on top of the gun-shaped handheld scanner. In both the integrated and non-integrated handheld scanner and data terminal systems, the user prefers to use the "precision hand" (i.e. the right hand for a right-handed person) for both aiming the scanner and keying in data entry. In either system, when manually keying in data, if the user is using the precision hand to hold and aim the scanner, the user must either switch the handheld unit to the "off" hand (i.e. the left hand for a right-handed person) or use his/her off hand to actuate keys on the data terminal. Alternately, the user would aim and use the scanner with the off hand to keep the precision hand free for manual data entry.